Lipase‐catalyzed synthesis of epigallocatechin gallate‐based polymer for long‐term release of epigallocatechin gallate with antioxidant property

Abstract

Epigallocatechin gallate (EGCG) must be released in a controlled manner in order to maximize its long-term potential as an antioxidant. In this study, lipase-catalyzed polymerization of EGCG with divinyl adipate and sugar alcohols was conducted to form poly-EGCG, which enables long-term controlled release of EGCG via hydrolysis of ester linkages. The polymer yields were influenced by monomer ratios, volume of solvent, and lipase concentration. EGCG was gradually released from polyEGCG under a physiological condition as ester groups of polyEGCG degraded over a period of more than two months, and the releasing rate was influenced by the type of the sugar alcohols and EGCG ratios. EGCG released from polyEGCG maintained its antioxidant activity and the cell viability of polyEGCG eluent with polymer concentration higher than 0.05 mg/mL was as high as 100%. These results indicate that polyEGCG has potential application as a highly efficient and long-term antioxidative material with low cytotoxicity.In this study, we synthesized a new polymer (polyEGCG) consisting of EGCG as a main component, divinyl adipate as a hydrophobic segment, and sugar alcohols as an elongation agent via esterification of divinyl adipate against EGCG and sugar alcohols (Scheme 1). As polyEGCG is introduced into a body transdermally, Additional Supporting Information may be found in the online version of this article.

Polymer Networks Synthesized from Poly(Sorbitol Adipate) and Functionalized Poly(Ethylene Glycol)

“…Here, the byproduct vinyl alcohol, which tautomerizes spontaneously to acetaldehyde, leaves the reaction as a gas. This process drives the reaction irreversibly in a forward direction [ 37 , 38 , 39 ]. The sugar alcohol sorbitol was selected since the two primary OH-groups are converted during the polycondensation process, but four secondary OH-groups per repeat unit of the polyester remain free, which guarantee the water solubility of PSA [ 40 ].…”

Recent advances in the enzymatic synthesis of lipophilic antioxidant and antimicrobial compounds

“…Three acetylated derivatives were identified and were better antioxidant agents in soybean oil than EGCG (Zhu et al 2017 ). In the study of Nitta and Iwamoto ( 2019 ), lipase-catalyzed polymerization of EGCG, divinyl adipate and sugar alcohols was investigated. The obtained poly(EGCG adipate- co -sugar alcohol-adipate)s have potential application in the cosmetics industry, because of the gradual release of EGCG, its antioxidant activity and non-toxicity to human neuroblastoma cells.…”